Given Saki's style as a comic relief character, I already assume she has a little bit of every popular fetish.
Ironically though, I can totally visualize a NTR scenario happening in this manga... Saki lets her imagination run wild and suddenly blurts out she wants see Naoya NTR'd, and then Naoya gets extremely determined to satisfy her suppressed desire, while saying that it'll be a purely physical relationship and not a romantic one... Well, there's zero chance the author will go there.